Good point, even as a pendulum you could use an item you would normally carry (Water or something as weight). The problem with the hand crank devices are unless your charging batteries or using it as a flashlight it consumes both hands. I had liked the pull cord idea because you can free up one hand and all the foot power ones are way to heavy.
_________________________
Failure is not an option!
USMC Jungle Environmental Survival Training PI 1985